• Journal of Ginseng Research
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• 제32권4호
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• pp.347-356
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• 2008

Forest-grown American ginseng (Panax quinquefolius L.) is exposed to daily and seasonal light variations. Our goal was to determine the effect of understory light changes on the maximum quantum yield of photosystem II, expressed as $F_v/F_m$, and photosynthetic pigment composition of two-year-old plants. Understory light photon flux density and sunfleck durations were characterized using hemispherical canopy photography. Our results showed that understory light significantly affected the $F_v/F_m$ of American ginseng, especially during the initial development of the plants when light levels were the highest, averaging 28 mol $m^{-2}d^{-1}$. Associated with low $F_v/F_m$ during its initial development, American ginseng had the lowest levels of epoxidation state of the xanthophyll cycle of the season, suggesting an active dissipation of excess light energy absorbed by the chlorophyll pigments. As photon flux density decreased after the deployment of the forest canopy to less than 10 mol $m^{-2}d^{-1}$, chlorophyll a/b decreased suggesting a greater investment in light harvesting pigments to reaction centers in order to absorb the fleeting light energy.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1998년도 추계학술대회
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• pp.86-87
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• 1998

To understand the developmental process of the gait pattern from infancy to the adult, a gait analysis for a 14 months female infant has been performed for ten weeks. The gait parameters has been measured every other week since the week when she was able to walk without aid. The infant gait data at the tenth week of the test shows a similar pattern to the adult gait in many aspects including initial knee flexion, initial ankle dorsiflexion, the push-off pattern, etc. There is not a significant change in the hip flexion angle from week to week from the two weeks after the test started. To check the individuality in the collected data, more infant subjects are being tested presently.

• PNF and Movement
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• 제16권1호
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• pp.143-150
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• 2018

Purpose: The purpose of this study was to investigate the influence of opposite lower extremity lateral muscle activation by proprioceptive neuromuscular facilitation (PNF) exercise targeting the lower extremities. Methods: Nineteen patients with chronic hemiplegia volunteered to participate in this study. PNF flexion, abduction, and internal rotation patterns; initial, end range, and extension patterns; abduction and internal rotation patterns; and initial and end range patterns were applied to the dominant lower extremity. Activation of lateral muscles (multifidus, gluteus medius, tensor fascia lata, and peroneous longus) of the paralyzed leg was then measured by electromyography (EMG). Results: There were significant differences in lateral muscle activation, depending on the PNF pattern applied, with the differences more significant in flexion, abduction, internal rotation, and end range patterns. Conclusion: PNF flexion, abduction, and internal rotation patterns can improve lateral muscle activation of one leg in the standing position in the gait cycle.

• 상하수도학회지
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• 제27권3호
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• pp.325-329
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• 2013

A result of estimating the effects of initial phosphorus concentration and nitrogen sources on removal of nitrogen and phosphorus in wastewater treatment using Scenedesmus dimorphus shows that there was no difference in microalgae growth amount and nitrogen removal amount by phosphorus concentration(5 ~ 60 mg/L). On the other hand, as initial phosphorus concentration increased, phosphorus removal amount was increased by luxury uptake of microalgae. Scenedesmus dimorphus preferred to ammonia when ammonia(40 mg/L) and nitrate(40 mg/L) are simultaneously presented and nitrogen removal rate of ammonia was high at approximately 20 mg/L/day.

• 센서학회지
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• 제27권6호
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• pp.368-373
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• 2018

The effects of long-term exposure of high and low humidity on thin-film humidity sensors are investigated. Five commercially available thin-film humidity sensors are initially calibrated in a humidity chamber as a reference before longterm exposure to high and low humidity. Then, the sensors are kept in a high-humidity environment (~95 %rh) for four months. After the exposure, the sensors are calibrated in the same manner as the initial calibration. Consequently, the device reading values from the humidity sensors are elevated up to about 5 %rh. Interestingly, the degree of elevation by the high-humidity exposure shows a negative correlation with the price of the humidity sensors. Humidity sensors are then kept in a low-humidity environment (~10 %rh) for another four months. After the exposure, a calibration similar to the initial calibration is performed. As a result, the device reading from humidity sensors is decreased, indicating a recovery from the effect of high-humidity exposure. The durability test conducted in this study provides experimental evidence for the use of thin-film humidity sensors in high-humidity environments such as greenhouses and food factories for a long period of time.

• 전기전자학회논문지
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• 제23권2호
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• pp.419-424
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• 2019

FCM 알고리즘은 반복 최적화 기법을 통해 최적해를 찾는다. 특히, 클러스터링 초기 중심과 잡음의 위치, 몰려있는 밀도의 위치, 개수에 따라 실행시간 차이가 난다. 하지만 이 방법은 중심점을 점차 갱신해 나가는 방법으로 초기 클러스터 중심이 한 쪽으로 치우치게 되고 클러스터링 결과의 편차가 심해 클러스터링 대푯값의 신뢰도가 떨어진다. 따라서 본 논문에서는 삼각부등식을 이용하여 클러스터 간 거리를 최대한 멀어지게 하여 클러스터 중심 밀도를 결정하는 TI-FCM(Triangular Inequality-Fuzzy C-Means:삼각부등식-FCM)클러스터링 알고리즘을 제안한다. 제안된 방법은 대용량의 빅데이터에서도 FCM에 비해 실제 클러스터에 수렴하는 효과적인 방법이고 실험을 통해 기존 FCM보다 실행시간이 감소됨을 보였다.

• Clinical and Experimental Pediatrics
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• 제59권10호
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• pp.408-413
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• 2016

Purpose: This study investigated predictors of unresponsiveness to second-line intravenous immunoglobulin (IVIG) treatment for Kawasaki disease (KD). Methods: This was a single-center analysis of the medical records of 588 patients with KD who had been admitted to Asan Medical Center between 2006 and 2014. Related clinical and laboratory data were analyzed by univariate and multivariate logistic regression analyses. Results: Eighty (13.6%) of the 588 patients with KD were unresponsive to the initial IVIG treatment and received a second dose. For these 80 patients, univariate analysis of the laboratory results obtained before administering the second-line IVIG treatment showed that white blood cell count, neutrophil percent, hemoglobin level, platelet count, serum protein level, albumin level, potassium level, and C-reactive protein level were significant predictors. The addition of methyl prednisolone to the second-line regimen was not associated with treatment response (odds ratio [OR], 0.871; 95% confidence interval [CI], 0.216-3.512; P=0.846). Multivariate analysis revealed serum protein level to be the only predictor of unresponsiveness to the second-line treatment (OR, 0.160; 95% CI, 0.028-0.911; P=0.039). Receiver operating characteristic curve analysis to determine predictors of unresponsiveness to the second dose of IVIG showed a sensitivity of 100% and specificity of 72% at a serum protein cutoff level of <7.15 g/dL. Conclusion: The serum protein level of the patient prior to the second dose of IVIG is a significant predictor of unresponsiveness. The addition of methyl prednisolone to the second-line regimen produces no treatment benefit.

• Radiation Oncology Journal
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• 제8권1호
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• pp.65-71
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• 1990

유방암의 일차 치료후 흉벽이나 국소임파절에 국한된 재발은 비교적 흔하게 관찰된다. 방사선치료는 이러한 국소재발유암 환자에게 효과적인 치료법으로 사용되어 왔으나 국소병변의 관해에도 불구하고 많은 경우에서 이차개발 또는 원격전이로 인해 불량한 예후를 보이므로 최근에는 다방면 병용요법을 시도하여 환자의 수명을 연장시키고 관해율을 증가시켰다는 고들이 있다. 이에 저자들은 국소 재발유암 환자의 특성과 치료결과, 치료후 실패양상, 생존율에 영향을 미치는 예후인자를 분석하여 향후치료의 지침으로 삼고자, 1974년 부터 1986년까지 연세대학교 의과대학 치료방사선과에서 방사선치료를 받은 53명을 대상으로 후향적분석을 통해 다음과 같은 결과를 얻었다. 32예 ($60.4\%$)가 단일 병소에, 21예 ($39.4\%$)가 다발병소에 재발하였다. 방사선치료후 31예 ($58.4\%$)에서 완전관해를 보였으나 그 중 7예는 치료부위에 다시 재발하였다. 전체환자의 5년 생존율과 무병생존율은 각각 $27\%,\;15\%$였다. 각각의 예후인자에 대한 단일변량분석에서는 최초 수술당시의 액와임파절전이 숫자, 보조적 화학요법의 시행 유무, 경도의 유무 등이 통계적 유의성을 보였고, 다변량분석법을 통한 분석에서는 최초수술당시의 액와임파절전이의 수, 경도의 유무, 재발시 병변의 크기, 치료후 관해기간 등이 생존율에 통계적으로 유의한 영향을 끼치는 예후인자였다.

• 대한임상검사과학회지
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• 제37권2호
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• pp.96-101
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• 2005

Status epilepticus is a medical emergency, so that rapid and vigorous treatment is required to prevent neuronal damage and systemic complication. Status epilepticus is generally defined as a continuous or intermittent seizure or an unconscious condition after the onset of seizure, lasting for 30 minutes or more. We report here the outcome of status epilepticus. We retrospectively reviewed medical record of 15 patients who were diagnosed with status epilepticus at the Asan Medical Center from January 2003 to February 2004. This outcome was evaluated considering various factors such as age of patients, history of seizures, neurologic impairment, etiology, mortality, return to baseline and initial electroencephalogram (EEG) findings. The range of age was between 1 to 79 years old and the longest duration of treatment was 118 days. Most patients were treated by using pentobarbital, midazolam, phenobarbital and other antiepileptic drugs. The overall mortality was 5 (33%) out of 15 patients. The mortality was related to etiology, underlying other medical conditions and initial EEG findings. 5 (55%) out of the 9 patients with acute etiology, 5 (71%) out of the 7 patients with a multifocal or burst-suppression EEG activity, and 3 (60%) out of the 5 patients with other medical disease were related to mortality. This data demonstrate high mortality due to status epilepticus. Mortality is related to etiology, other medical conditions and abnormalities on the initial EEG.

• Journal of Applied Biological Chemistry
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• 제56권2호
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• pp.119-129
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• 2013

Thirteen different Streptomyces isolates were evaluated for their ability to produce keratinase using chicken feather as a sole carbon and nitrogen sources under solid state fermentation (SSF). Streptomyces sp. NRC 13S produced the highest keratinase activity [1,792 U/g fermented substrate (fs)]. The phenotypic characterization and analysis of 16S rDNA sequencing of the isolate were studied. Optimization of SSF medium for keratinase production by the local isolate, Streptomyces sp. NRC13S, was carried out using the one-variable-at-a-time and the statistical approaches. In the first optimization step, the effect of incubation period, initial moisture content, initial pH value of the fermentation medium, and supplementation of some agro-industrial by-products on keratinase production were evaluated. The strain produced about 2,310 U/gfs when it grew on chicken feather with moisture content of 75% (w/w), feather: fodder yeast ratio of 70:30 (w/w), and initial pH 7 using phosphate buffer after 8 days. Based on these results, the Box-Behnken design and response surface methodology were applied to find out the optimal conditions for the enzyme production. The corresponding maximal production of keratinase was about 2,569.38 U/gfs.